1. Field of the Invention
This invention generally relates to an automatic chemical analyzing apparatus and in particular to an improved multi-item automatic chemical analyzing apparatus having enhanced analyzing capability.
2. Discussion of Background
For chemical analyses carried out in series, there are used to an increasing extent chemical analyzers which carry out automatically the sampling, the adding of reagents, the provision for the suitable reaction conditions occurring in the course of analyses, the measurement, the display and recordation of the data. Such devices are used, e.g. in hospitals and clinics, where a large number of measurements must be carried out in a short time.
Many automatic chemical analyzing apparatus, such as disclosed in U.S. Pat. No. 3,622,279, in current use can simultaneously analyze one or more test items. Such analyzers include a plurality of reaction lines used for respective specific tests without any item change, and are called a multi-channel automatic chemical analyzer.
An analyzer as shown in U.S. Pat. No. 3,660,638 includes only one reaction line (meaning a path along which reaction tubes are arranged in a line or a pipe through which samples spaced by bubbles pass) to take a multi-item (multi-component) measurement. Such a known one-line automatic chemical analyzer is of a type in which each of the samples is successively analyzed in terms of a plurality of specific items, or a type in which the same reaction line is used and all associated samples are first analyzed in terms of one item and then in terms of another item after the end of analysis of the one item.
In the above-mentioned apparata, the multi-channel automatic chemical analyzer is operated at very poor efficiency with disadvantageous operation of unnecessary reaction lines for the non-selected test items of each sample because the typical samples, being individually observed, do not require test of all of the possible items capable of being tested. Further, in the single channel automatic chemical analyzer, it takes more time to obtain results about all the test items of one sample if the test items increase in number with respect to the individual samples, or the samples to be analyzed increase, and it is difficult to eliminate the contamination between the different reagents supplied in series to the same cuvette because of a failure to clean completely the cuvette in the elapsed time.
In addition, many chemical reactions must be analyzed over a period of 5 minutes or more so as to measure the rate of reaction with high accuracy, so that the analysis generally proceeds slowly. This is contrary to increasing the sample processing speed. However, this requirement is very important to achieve an accurate measurement of the samples.